How Corrective Lenses Work

One of the most common sights almost anywhere in the world is -- eyeglasses! Since we depend so much on the lenses inside those frames to improve our view of the world, you might wonder just what goes into creating them.

In this a­rticle, we will talk about how the eye focuses, how a lens works, how to read a prescription, and finally, how the lens is made, including the steps involved in grinding and shaping plastic lens blanks to fit an individual's prescription and frame.

Let's start with some vision basics.

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Test your eyes

Try this interactive activity from Discovery Channel -- test your sight and learn how vision works at the same time. Other interactive segments let you explore your body's systems and see how they help you move smoothly through your daily life.